Thread cutter for sewing machines



H. L. WILLIS THREAD CUTTER FOR sw ne MACHINES Filed Jan. 2. 1924 IIHHWK .1. Ill

Patented Feb. 24, 1925..

UNITED STATES 1,527,245 PATENT OFFICE,

HARRY L. WILLIS, OF CHICAGO, ILLINOIS, ASSIGNOE T0 UNIO'N SPECIAL MACHINE COMPANY, 01 CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

THREAD CUTTER FOR SEWING MACHINES.

Application filed January 2, 1924. Serial no. 683,976.

. a description, reference being had to the accompanying drawings, and to the figures of reference marked thereen. The invention relatesto new and useful improvements in'sewing machines, and more particularly to thread cutters adapted to cut a thread extending from a stitched article to the stitching mechanism.

*Prior to my invention, it has been the practice to provide certain types of machines with a thread cutter which is attached to the presser bar and so arranged that the thread extending between a stitched article and the stitching element may be drawn across the cutter for severing the thread. In certaintypes of machines, a thread cutter of this character. cannot be used as, for example, in

a sewing machine having a feed dog working above the material an along side of the presser foot, wherein said feed dog is op-' erated through a connection extending in rear of the presser foot and beneath the work support where it is attached to a feed bar.

An object of the present invention is to provide a thread cutter for a machine pf the above type, and in carrying out the lnvention, I have provided means whereby a thread cutter may be mounted on the shank portion of the upper feed dog. In the drawings, which show b way of illustration one embodiment of t e invention:-

- Figure 1 is a perspective view showing a machine embodying my invention;

Fig. 2 is a top plan view of the upper feed dog with my improved thread cutter attached thereto;

Fig. 3 is a top plan view of the upper cutting section;

Fig. 4 is a top planview of the lower thread cutting section;

Fig. 5 is a top plan view of the feed dog with the thread cutter removed;

" Fig. 6 is a side view of the u per feed dog with m improvements applie thereto;

Fig. is a sectional view on the l ne 7-.-7

or Fig. 4;,

and presser foot 3 'havin The machine to which my invention is apphed 1s an ordinary flat bed machine having a feed dog beneath the work support which prO ects through a slot in the throat plate for engagement with the material for feeding the same. Cooperating with this lower feed dog is an upper feed dog'which iscarrled by a supporting shank attached to a feed bar beneath the work support, which shank extends from beneath the work'support above the same and around therear of the presser foot, and sup orts a feed dog referably formed integral therewith which ies alongside of the presser foot and cooperates with the lower feed dog above the work support. Such a machine ,is shown in Patent No. 591,517, granted to R. G. Wood ward, October 12, 1897, and .consists of a work support 1 having a lower feed dog 2 a needle hole 4; therethrough through which the needle reciprocates. Said presser foot is carried by a presser bar 5. Cooperating with this lower feed dog 2 is an upper feed dog 6 which consists of a shank portion 7 with which the feed portion 6 is integrally formed. This shank 'ortion 7 is curved so as to extend around 1: e heel or rear of the presser foot 3 and has a. depending portion 8 which extends through a slot in the work support and is attached to a lower feed bar after the manner shown in the patent referred to above. i

The shank portion of the feed dog is provided with two threaded openings 9 and 10. The thread cutter is composed of two members 11 and 12. The member 11 is the lower member and is attached directly to the U sha ed portion 7 of the shank, of the upper fee dog. Said lower portion of the cutter is provided with two openings 13 and 14 which are adapted to register respectively with the openin 9 and 10 in the shank of the feed dog. aid lower portion has a V- shaped notch 15, the ed e 16 of which is beveled as shown in Fig i.

The upper member 12 of the thread cutter I gated 0 ening 19, the opening 14 and is threade into the opening 10. A nut 22 is threaded onto this bolt and serves as a means for clamping the two sections of the thread cutter together and against the shank of the upper feed dog. This threaded bolt 21 is also used for supporting the feed dog in its variousadjusted positions as to height after the manner set forth in the VVoodward patent, and it performs the function in in the present instance through the nut 22 of rigidly supporting the members of the thread cutter.

The two sections are so arranged, when attached to the feed dog, that the beveled edge 17 overlies and intersects the beveled edge 16, thus forming a V-shaped opening into which the thread may be drawn for bringing it against these beveled edges for the purpose of severing the thread.

In stitching an article, the operator runs the article through from beneath the resser foot and, at the same time, forms a 0 sin of thread. Then the article is lifted by the operator, brought forward over top of t e thread cutter, and the thread laid into said notch in the thread cutter. A slight pull onthe chain will draw it against the beveled edges of the thread cutter and sever the same.

The elongated openings in the upper member of the thread cutter aflt'ord a means for adjusting the upper section as it is ground to keep the beveled edge sharp, and thus bring the beveled edges into proper cooperation for severing the thread. It will be understood, of course, that, when the thread is cut, the machine is not running and, therefore, the upper feed dog is stationary, and this enables the thread to be laid into the thread cutter and severed without any difiiculty. By having the threaded bolt 21, as well as the threaded screw 20, for securing the two members of the cutter together to the feed dog, I am able to provide a very rigid support for the thread cutting members, wherein said members will not be dis turbed in any way by pulling up the thread thereagainst when the thread 15 to be severed. It is obvious that minor changes in the details of construction and the arrangement of the arts may be made without departin from t e spirit of the invention as set fort in the appended claims.

What I claim as new is 1. In a sewing machine, the combination with a resser foot, an upper feed dog supported eneath the work support and extendmg around in rear of the presser foot, of a thread cutter mounted on said feed dog and disposed so that the thread leading from the stitching mechanism to a stitched article may be drawn across said thread cutter for severing the thread.

2. In a sewing machine, thecombination with a presser foot, an u per feed dog extending along side of sai presser foot and supported by a shank extending in rear of the presser foot, of a thread cutter including two coo crating sections rigidly secured to the shanr on the feed dog and disposed so as to form a V-shaped cutting notch facing rearwardly and ada ted to receive the thread extendin from t e stitching mechanism to a stitc ed article and laid thereagainst by the operator.

3. In a sewing machine, the combination with a presser foot, an upper feed dog including a feeding portion extending along side of the presser foot, a shank portion extending in rear of the presser foot and car ried beneath the work support, a thread.

cutter including a lower section conforming to the shank of the feed dog in rear of the presser foot, an upper section likewise conforming to the section of the feed dog in rear of the presser foot, means for securing said sections of the cutter to the shank of the feed dog, said lower section having a projecting portion shaped so as to form one wall of a V-shaped notch with its edges beveled, said upper section being Sb. (1 so as to form the other wall of a V-shape notch having its edge beveled, said V-shaped notch opening rearwardly so that an operator may draw the thread, connecting the stitching mechanism to a stitched article into said notch for the severing of the thread.

In testimony whereof, I aflix my si ature.

HARRY L. LIS. 

